Harvard University is a private Ivy League research university in Cambridge, Massachusetts, whose history, influence and wealth have made it one of the most prestigious universities in the world. Established in 1636 by the Massachusetts legislature and soon thereafter named for John Harvard (its first benefactor), Harvard is the United States' oldest institution of higher learning, and the Harvard Corporation (formally, the President and Fellows of Harvard College) is its first chartered corporation. Although never formally affiliated with any denomination, the early College primarily trained Congregation?alist and Unitarian clergy. Its curriculum and student body were gradually secularized during the 18th century, and by the 19th century Harvard had emerged as the central cultural establishment among Boston elites. Following the American Civil War, President Charles W. Eliot's long tenure (1869?1909) transformed the college and affiliated professional schools into a modern research university; Harvard was a founding member of the Association of American Universities in 1900. James Bryant Conant led the university through the Great Depression and World War II and began to reform the curriculum and liberalize admissions after the war. The undergraduate college became coeducational after its 1977 merger with Radcliffe College.The University is organized into eleven separate academic units?ten faculties and the Radcliffe Institute for Advanced Study?with campuses throughout the Boston metropolitan area: its 209-acre (85 ha) main campus is centered on Harvard Yard in Cambridge, approximately 3 miles (5 km) northwest of Boston; the business school and athletics facilities, including Harvard Stadium, are located across the Charles River in the Allston neighborhood of Boston and the medical, dental, and public health schools are in the Longwood Medical Area. Harvard has the largest financial endowment of any academic institution in the world, standing at $32.3 billion as of June 2013 Harvard is a large, highly residential research university. Its undergraduate program (comprising a minority of enrollments) emphasizes an ""arts and sciences focus"", while the graduate programs have a larger variety of disciplinary degrees offered. The nominal cost of attendance is high, but the University's large endowment allows it to offer generous financial aid packages. It operates several museums, and the Harvard University Library is the oldest library system in the United States, the largest academic and the largest private library system in the world.It has many eminent alumni. Eight U.S. presidents and several foreign heads of state have been graduates. It is also the alma mater of 62 living billionaires and 335 Rhodes Scholars, the most in the country. To date, some 150 Nobel laureates have been affiliated as students, faculty, or staff.